U.S. President Barack Obama delivers a much-anticipated closing night address Thursday before the Democratic National Convention in Charlotte, North Carolina.

Nine weeks ahead of the November 6th general election, and in a virtual tie with his Republican challenger, former Massachusetts Governor Mitt Romney, Mr. Obama aims to use his nationally-televised nomination acceptance speech to convince undecided voters to re-elect him to a second White House term.

The president's campaign received a major boost Wednesday with a rousing speech by former President Bill Clinton, who remains a popular figure among many Americans who recall the economic prosperity during his two terms in office in the 1990's.

Mr. Clinton offered a strong defense of the current president's economic record against Republican claims that conditions have worsened since Mr. Obama took office in 2009.

“When President Barack Obama took office, the economy was in free fall. It had just shrunk nine full percent of GDP. We were losing 750,000 jobs a month. Are we doing better now today? The answer is YES.”

Mr. Obama walked on stage after Mr. Clinton's speech, and the two men enjoyed a warm handshake and embrace.

Vice President Joe Biden will take the stage before Mr. Obama to accept the nomination as the president's second-term running mate.

Democratic convention officials say they were forced to cancel plans to stage Mr. Obama's and Mr. Biden's speeches at Charlotte's 74,000-seat outdoor football stadium because of the possibility of rainstorms. They will instead speak in the much smaller, 20,000-seat indoor arena that has hosted the rest of the convention.

Mr. Obama's Republican opponents said the real worry for his supporters was that the president might not attract enough people to fill the huge stadium.